As is known, the 2-hydroxy-N,N,N-trimethylethanaminium salt of 3,7-dihydro- 1,3-dimethyl-1H-purine-2,6-dione (1 : 1) (choline theophyllinate) is a pharmacologically effective compound contained as the active ingredient in broncholytically active medicines ("Rote Liste 1980" [Red List 1980] Editio Cantor Publishers, Aulendorf, Wuerttemberg DT, No. 27 042). This salt of theophylline has the advantage over other salts of this compound, for example, theophylline ethylenediamine (=aminophylline), of being more compatible. (Arzneim. Forsch., 31 : 1503 et seq., 1981, and 32 : 409 et seq., 1982). The preparations containing choline theophyllinate are administered orally. As a consequence, the active agent concentration in the blood plasma reaches its maximum only after about two hours (Brit. J. Pharmacol. 3 : 194-196, 1976), which is a disadvantage especially in the treatment of grave, spasmodic conditions. There is thus a need for injection media containing this active ingredient.
Aqueous solutions of choline theophyllinate are unstable and accordingly unsuitable for injection media. An attempt at stabilizing these solutions by adding acids or antioxidants customarily employed in galenic pharmacy (formic acid, acetic acid, phosphoric acid, benzoic acid, glutaric acid, adipic acid, sorbic acid, malic acid, tartaric acid, ascorbic acid, citric acid, etc.) results in precipitation of the choline theophyllinate, or solutions are obtained that are likewise unstable, discoloring, and unsterilizable.